Vehicles that are utilized to go off-road for sport and recreation, or utilized for work which requires long hours of driving, often require refueling in locations devoid of easily accessible fueling stations. Driving back to a fueling station in such situations can be difficult and time consuming, limiting the utility of the vehicle. One option for reducing trips to a fueling station is to increase the fuel capacity of the vehicle by installing an auxiliary fuel system.
An auxiliary fuel system must meet certain standards in order to prevent voiding vehicle manufacturer warrantees and comply with EPA and DOT regulations. An efficient way to meet such standards and regulations is to avoid drilling into the primary fuel tank or tapping into downstream fuel transfer lines. This can be accomplished by transferring fuel into the primary fuel system upstream of the primary fuel tank. However, this setup requires the auxiliary fuel system to monitor the fuel level in the primary fuel tank in order to determine when to start transferring fuel (e.g., when the level of fuel in the primary tank reaches a certain point such as, without limitation, ¼ capacity), and when to stop transferring fuel (e.g., when the primary fuel tank is substantially full, and/or when the auxiliary tank is empty).
Existing automatic fuel transfer systems include an auxiliary fuel tank that is installed on a vehicle, a pump, and a controller that monitors the fuel levels of the primary fuel tank and auxiliary fuel tank and controls the pump. When the controller detects that the primary fuel tank is low, it automatically causes fuel to be pumped from the auxiliary tank into the primary tank. In order to detect when the primary tank is low, existing systems require tapping into a wire leading from a sensor in the fuel tank (the sending unit) which monitors the level of fuel in the primary tank. The information from this sensor (ordinarily a voltage provided from the sending unit) is used by the vehicle fuel gauge to display the current level of fuel in the primary tank. However, this system is not ideal as different makes and models of vehicles use different sending units which provide different voltages to different fuel gauges, so each time an existing controller is installed on a vehicle, it must be set up to correspond to the voltage range used by that particular vehicle. It can also be challenging to identify and tap into the correct wire leading from the primary fuel tank sending unit each time a controller is installed, and to connect that wire, which is in the engine compartment, to the auxiliary fuel controller unit, which is preferably located in the cabin of the vehicle. This can be a tedious and time-consuming process, often requiring trial and error to make sure that the correct wire has been tapped into, and may require drilling through the wall between the cabin and the engine compartment.
It is therefore desirable to provide auxiliary fuel tank control systems and methods of use that monitor the levels of fuel in a vehicle's primary fuel tank and auxiliary fuel tank, and that may be installed without having to identify and tap into a wire leading from the sending unit of the primary fuel tank, thereby avoiding guesswork and assuring proper installation and operation of the system.